Buggy code:
public static void registerModelBuilder ( String name , Class < ? extends ModelBuilder > clz ) { } public static Map < String , Class < ? extends ModelBuilder > > getModelBuilders ( ) { } public static Class < ? extends ModelBuilder > getModelBuilder ( String name ) { } public static Class < ? extends Model > getModelClass ( String name ) { } public static String getAlgo ( Model model ) { } public static String getModelBuilderName ( Class < ? extends ModelBuilder > clz ) { } public abstract ModelBuilderSchema schema ( ) { } public ModelBuilder ( P ignore ) { } public ModelBuilder ( String desc , P parms ) { } public ModelBuilder ( Key dest , String desc , P parms ) { } public static ModelBuilder createModelBuilder ( String algo ) { } public abstract Job < M > trainModel ( ) { } public abstract ModelCategory [ ] can_build ( ) { } public void clearInitState ( ) { } public void init ( boolean expensive ) { if ( expensive ) { Log . info ( ( ( "Building<seq2seq4repair_space>H2O<seq2seq4repair_space>" + ( this . getClass ( ) . getSimpleName ( ) . toString ( ) ) ) + "<seq2seq4repair_space>model<seq2seq4repair_space>with<seq2seq4repair_space>these<seq2seq4repair_space>parameters:" ) ) ; Log . info ( new GsonBuilder ( ) . setPrettyPrinting ( ) . create ( ) . toJson ( new JsonParser ( ) . parse ( new String ( _parms . writeJSON ( new AutoBuffer ( ) ) . buf ( ) ) ) ) ) ; } clearInitState ( ) ; assert ( _parms ) != null ; if ( ( _parms . _train ) == null ) { error ( "_train" , "Missing<seq2seq4repair_space>training<seq2seq4repair_space>frame" ) ; return ; } Frame tr = _parms . train ( ) ; if ( tr == null ) { error ( "_train" , ( "Missing<seq2seq4repair_space>training<seq2seq4repair_space>frame:<seq2seq4repair_space>" + ( _parms . _train ) ) ) ; return ; } _train = new Frame ( null , tr . _names . clone ( ) , tr . vecs ( ) . clone ( ) ) ; if ( ( _parms . _ignored_columns ) != null ) { _train . remove ( _parms . _ignored_columns ) ; if ( expensive ) Log . info ( ( "Dropping<seq2seq4repair_space>ignored<seq2seq4repair_space>columns:<seq2seq4repair_space>" + ( Arrays . toString ( _parms . _ignored_columns ) ) ) ) ; } String cstr = "" ; for ( int i = 0 ; i < ( _train . vecs ( ) . length ) ; i ++ ) { if ( ( _train . vecs ( ) [ i ] . isConst ( ) ) || ( _train . vecs ( ) [ i ] . isBad ( ) ) ) { cstr += ( _train . _names [ i ] ) + ",<seq2seq4repair_space>" ; _train . remove ( i ) ; i -- ; } } if ( ( cstr . length ( ) ) > 0 ) if ( expensive ) Log . info ( ( "Dropping<seq2seq4repair_space>constant<seq2seq4repair_space>columns:<seq2seq4repair_space>" + cstr ) ) ; if ( _parms . _dropNA20Cols ) { String nstr = "" ; for ( int i = 0 ; i < ( _train . vecs ( ) . length ) ; i ++ ) { float ratio = ( ( float ) ( _train . vecs ( ) [ i ] . naCnt ( ) ) ) // ( _train . vecs ( ) [ i ] . length ( ) ) ; if ( ratio > 0.2 ) { nstr += ( ( ( _train . _names [ i ] ) + "<seq2seq4repair_space>(" ) + ( String . format ( "%.2f" , ( ratio * 100 ) ) ) ) + "%),<seq2seq4repair_space>" ; _train . remove ( i ) ; i -- ; } } if ( ( nstr . length ( ) ) > 0 ) if ( expensive ) Log . info ( ( "Dropping<seq2seq4repair_space>columns<seq2seq4repair_space>with<seq2seq4repair_space>too<seq2seq4repair_space>many<seq2seq4repair_space>missing<seq2seq4repair_space>values:<seq2seq4repair_space>" + nstr ) ) ; } if ( ( _train . numCols ( ) ) == 0 ) <START_BUG> error ( "_train" , "There<seq2seq4repair_space>are<seq2seq4repair_space>no<seq2seq4repair_space>usable<seq2seq4repair_space>columns<seq2seq4repair_space>to<seq2seq4repair_space>the<seq2seq4repair_space>generate<seq2seq4repair_space>model" ) ; <END_BUG> Frame va = _parms . valid ( ) ; if ( va != null ) _valid = new Frame ( null , va . _names . clone ( ) , va . vecs ( ) . clone ( ) ) ; try { String [ ] msgs = Model . adaptTestForTrain ( _train . _names , _train . domains ( ) , _valid , _parms . missingColumnsType ( ) , expensive ) ; if ( expensive ) for ( String s : msgs ) Log . info ( s ) ; } catch ( IllegalArgumentException iae ) { error ( "_valid" , iae . getMessage ( ) ) ; } assert ( ! expensive ) || ( ( ( _valid ) == null ) || ( Arrays . equals ( _train . _names , _valid . _names ) ) ) ; } public ModelBuilder . ValidationMessage [ ] _messages = new ModelBuilder . ValidationMessage [ 0 ] ; private int _error_count = - 1 ; public int error_count ( ) { } public void hide ( String field_name , String message ) { } public void info ( String field_name , String message ) { } public void warn ( String field_name , String message ) { } public void error ( String field_name , String message ) { } private void clearValidationErrors ( ) { } private void message ( ModelBuilder . ValidationMessage . MessageType message_type , String field_name , String message ) { } public String validationErrors ( ) { } public static final class ValidationMessage extends Iced { public enum MessageType { HIDE , INFO , WARN , ERROR ; } final ModelBuilder . ValidationMessage . MessageType message_type ; final String field_name ; final String message ; public ValidationMessage ( ModelBuilder . ValidationMessage . MessageType message_type , String field_name , String message ) { }

Fix:
error ( "_train" , "There<seq2seq4repair_space>are<seq2seq4repair_space>no<seq2seq4repair_space>usable<seq2seq4repair_space>columns<seq2seq4repair_space>to<seq2seq4repair_space>generate<seq2seq4repair_space>model" ) ;